High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications

Xu, Yong; Jin, Zhenhu; Chen, Jiamin

doi:10.3390/mi16020136

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Open AccessArticle

High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications

by

Yong Xu

^1,2,

Zhenhu Jin

^1,2,* and

Jiamin Chen

^1,2,3,*

¹

State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China

²

School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China

³

College of Materials Sciences and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China

^*

Authors to whom correspondence should be addressed.

Micromachines 2025, 16(2), 136; https://doi.org/10.3390/mi16020136

Submission received: 3 January 2025 / Revised: 18 January 2025 / Accepted: 23 January 2025 / Published: 24 January 2025

(This article belongs to the Special Issue Micro and Nanosensors: Fabrication, Applications and Performance Enhancements, 2nd Edition)

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Abstract

To meet the demand for high-precision, high-resolution measurement of weak currents in smart grids, this article presents the design of a current sensor based on the tunneling magnetoresistance (TMR) effect. To improve the detection accuracy of the sensor, this design adopts a low-noise, high-sensitivity TMR chip as its chip selection; in the sensor circuit, a high-linearity interface circuit is used to eliminate fixed bias; and a magnetic flux concentrator is used to improve sensitivity and anti-interference capability. Experimental results indicate that the sensor achieves a sensitivity of 29.4 mV/V/mA, a linearity of 0.19%, and an accuracy of 0.045% within a ±100 mA range, supporting current measurement from DC up to 10.5 kHz. The proposed sensor demonstrates several advantages, including a wide measurement range, high accuracy, high resolution, and non-invasive measurement capability, making it well suited for weak current detection in smart grid applications.

Keywords: tunneling magnetoresistance current sensor; smart grid; leakage current detection; non-contact

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MDPI and ACS Style

Xu, Y.; Jin, Z.; Chen, J. High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications. Micromachines 2025, 16, 136. https://doi.org/10.3390/mi16020136

AMA Style

Xu Y, Jin Z, Chen J. High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications. Micromachines. 2025; 16(2):136. https://doi.org/10.3390/mi16020136

Chicago/Turabian Style

Xu, Yong, Zhenhu Jin, and Jiamin Chen. 2025. "High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications" Micromachines 16, no. 2: 136. https://doi.org/10.3390/mi16020136

APA Style

Xu, Y., Jin, Z., & Chen, J. (2025). High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications. Micromachines, 16(2), 136. https://doi.org/10.3390/mi16020136

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

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High-Precision Tunneling Magnetoresistance (TMR) Current Sensor for Weak Current Measurement in Smart Grid Applications

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